Nov. 21 is the 42nd anniversary of the first permanent ARPANET link; the Internet's beginning

Nov. 21 marks the
42nd anniversary
of the first permanent Advanced Research Projects Agency Network (ARPANET) link between UCLA's Interface Message Processor (IMP) and the IMP at the
Stanford Research Institute
. By Dec. 5, 1969, the original four-node ARPANET environment was set up. History notes this network as the world's first operational packet switching network and the core of what is today’s Internet. UCLA recently opened the Kleinrock Internet Heritage Site and Archive in honor of the ARPANET project’s overseer Professor Leonard Kleinrock, to preserve and celebrate the birthplace of the Internet. The first message between the nodes had been sent by Kleinrock on Oct. 29, 1969.

UCLA's Interface Message Processor (IMP) here, in the birthplace of the Internet, at 3420 Boelter Hall, the original location of the first ARPANET node at UCLA in Los Angeles. UCLA professor Leonard Kleinrock and his team used the IMP, the packet-switching node used to interconnect participant networks to the ARPANET to send the first message to Stanford Research Institute on Oct. 29, 1969.

Pictured here is a visitor to the grand opening of the Kleinrock Internet Heritage Site and Archive in 3420 Boelter Hall, the birthplace of the Internet. The recreated lab features a replica of the Sigma 7 computer, a teletype similar to one used to communicate with the SIGMA 7 computer, which was connected to UCLA's IMP.

The IMP in the storage closet where it had been stored for over 20 years, at 3420 Boelter Hall in UCLA. The UCLA Department of Computer Science and Henry Samueli School of Engineering and Applied Science have opened the Kleinrock Internet Heritage Site and Archive (KIHSA) and moved the IMP from the closet to its current resting place.

The blackboard with the letters LOG and LO, is pictured in 3420 Boelter Hall at UCLA. UCLA professor Kleinrock and his team used the IMP, to interconnect participant networks to the ARPANET to send the first message, the letters LO to Stanford Research Institute on Oct. 29, 1969. Kleinrock was trying to write "login," starting up a remote time-sharing system, but the system crashed after two letters, and lo was all it sent.

Internet technology consultant Charely Kline (foreground) stands next to a teletype similar to the one used to communicate with the Sigma 7 computer at the grand opening of the Kleinrock Internet Heritage Site and Archive.

Pictured here, Distinguished Professor of Computer Science at UCLA professor Leonard Kleinrock speaks as his granddaughter Rosa Schorr peeks out from the podium at the grand opening of the Kleinrock Internet Heritage Site and Archive in October.

Computer scientist Stephen Casner speaks at the grand opening of the Kleinrock Internet Heritage Site and Archive. Casner and fellow researcher Danny Cohen, working at the University of Southern California, designed and implemented protocols and software for some of the earliest experiments with packet voice using the ARPANET.